Objective: We determined the effectiveness of a multi-strain probiotic-prebiotic combination on constipation symptoms and gut motility in PD patients with constipation.

Methods: PD patients with constipation (ROME III criteria) were randomized to receive a multi-strain probiotic (Lactobacillus sp and Bifidobacterium sp at 30 X 10⁹ CFU) with fructo-oligosaccaride (prebiotic) or placebo (fermented milk) twice daily for 8 weeks. Primary outcomes were changes in the presence of constipation symptoms using 9 items of Garrigues Questionnaire (GQ), which included an item on bowel opening frequency. Secondary outcomes were whole gut transit time (WGTT), quality of life (PDQ39-SI), motor (MDS-UPDRS) and non-motor symptoms (NMSS).

Results: Of 55 recruited, 48 patients completed the study: 22 received probiotic and 26 received placebo. At 8 weeks, the item on bowel opening frequency (BOF) of GQ showed  a higher mean weekly BOF in the probiotic group compared to placebo [4.18 (SD 1.44) vs 2.81(SD 1.06), (mean difference 1.37, 95% CI 0.68, 2.07, uncorrected p<0.001). Patients in the probiotic group reported five times higher odds (odds ratio=5.48, 95% CI 1.57, 19.12, uncorrected p=0.008) for increasing BOF (< 3 to 3-5 to >5 times/week) compared to the placebo group. Between-group differences were observed in the WGTT [77.32 (SD 55.35) hours vs 113.54 (SD 61.54) hours], (mean difference -36.22, 95% CI -68.90, -3.54, uncorrected p=0.030) and the mean change in WGTT [58.05 (SD 59.30) vs 20.73 (60.48) hours], (mean difference 37.32, 95% CI 4.00, 70.63, uncorrected p=0.028). No between-groups differences were observed in the NMSS, PDQ39-SI, MDS-UPDRS II, III, scores. Four patients in the probiotics group experienced mild reversible side effects.

Conclusion: This study provides Class I evidence that consumption of multi-strain probiotics with prebiotic over 8 weeks improved bowel opening frequency and whole gut transit time.